The purpose of the study was to determine associations between metabolic syndrome severity and cognitive performance, and the moderating effects of vascular health. In 48 older adults, MetS severity score was negatively correlated with reaction time (r=-0.379, p=0.010) and accuracy (r=-0.351, p=0.023) on a task of working memory. MetS severity was also positively correlated to arterial stiffness (r=0.501, p<0.001). The severity of MetS should be considered an important variable on cognitive decline in this population.